NSScreen instances can be garbage collected at any time, even for
screens that remain connected, making NSMapTable with weak keys
unreliable for tracking per-screen state.
This changes the quick terminal to use CGDisplay UUIDs as stable
identifiers, keyed in a strong dictionary. Each entry stores the
window frame along with screen dimensions, scale factor, and last-seen
timestamp.
Rules for pruning:
- Entries are invalidated when screens shrink or change scale
- Entries persist and update when screens grow (allowing cached state
to work with larger resolutions)
- Stale entries for disconnected screens expire after 14 days.
- Maximum of 10 screen entries to prevent unbounded growth
Lukas